Maya Yoshida felt Southampton missed a huge opportunity to capitalise on a depleted home team after the 2-1 defeat at Tottenham Hotspur Stadium.
Saints found themselves on level terms after Danny Ings pounced on a Hugo Lloris mistake to equalise against a Spurs side who were down to ten men from the 31st minute.
But the hosts soon went back in front, and Saints were unable to break them down for a second time after the interval, with Yoshida denied by a stunning Lloris save from the pick of the chances.
“I think we missed a huge opportunity to win against a big team today,” the defender said.
“Obviously it’s a huge disappointment for myself, but if we have the chance we have to take it, otherwise it will get more difficult.
“After Aurier was sent off, we were too passive. We have to be much more aggressive, and after we conceded the second goal in a sloppy way, it became more difficult for us.
“In the second half, we needed more creativity in the attacking third. They defended very well, but for myself, I needed to score from the corner kick.
“Again, there was an opportunity and we couldn’t take it. Now it’s a really difficult situation for ourselves, but we cannot look behind us too much.
“It’s another important game against Chelsea next week, so we’ll focus on that and keep going.”